我使用DB浏览器的SQLite。我有以下格式的表:
+-----------+-------------------------------------+
| search_id | search_town |
+-----------+-------------------------------------+
| 1 | town1,town3 |
| 2 | town2,town4,town5 |
| 3 | town3,town5 |
| 4 | town2,town5 |
| 5 | town2,town3,town4 |
+-----------+-------------------------------------+
我想这样做对的次数的COUNT
town1
通过town5
已根据search_town
出现,然后根据各自的计数降序排列的城镇。到目前为止,我有以下查询:
SELECT SUM(CASE WHEN search_location LIKE '%town01%' THEN 1 ELSE 0 END) AS town01,
SUM(CASE WHEN search_location LIKE '%town02%' THEN 1 ELSE 0 END) AS town02,
SUM(CASE WHEN search_location LIKE '%town03%' THEN 1 ELSE 0 END) AS town03,
SUM(CASE WHEN search_location LIKE '%town04%' THEN 1 ELSE 0 END) AS town04,
SUM(CASE WHEN search_location LIKE '%town05%' THEN 1 ELSE 0 END) AS town05
FROM searches
......但我无法做一个ORDER BY
作为城镇和他们的罪名是因为这种格式列而非行输出
+-------+-------+-------+-------+-------+
| town1 | town2 | town3 | town4 | town5 |
+-------+-------+-------+-------+-------+
| 12 | 31 | 12 | 24 | 12 |
+-------+-------+-------+-------+-------+
是否有其他方法吗?欣赏任何意见。
您正在使用CASE WHEN
,将其转换成多行把你的输出单行,你可以尝试像以下。
;WITH cte
AS (SELECT *
FROM (VALUES ('Town1'),
('Town2'),
('Town3'),
('Town4'),
('Town5')) T(town))
SELECT Count(*) [Count],
C.town
FROM [TABLE_NAME] T
INNER JOIN cte C
ON T.search_location LIKE '%' + C.town + '%'
GROUP BY C.town
ORDER BY Count(*) DESC
另一种方法可以是使用UNION ALL
。
SELECT *
FROM (SELECT Count(*) s,
'Town1' AS Col
FROM tablename
WHERE search_location LIKE '%town1%'
UNION ALL
SELECT Count(*) s,
'Town2' AS Col
FROM tablename
WHERE search_location LIKE '%town2%'
UNION ALL
SELECT Count(*) s,
'Town3' AS Col
FROM tablename
WHERE search_location LIKE '%town3%'
UNION ALL
SELECT Count(*) s,
'Town4' AS Col
FROM tablename
WHERE search_location LIKE '%town4%'
UNION ALL
SELECT Count(*) s,
'Town5' AS Col
FROM tablename
WHERE search_location LIKE '%town5%') t
ORDER BY s DESC
您可以使用递归公用表表达式(CTE)打开逗号分隔的列表为一组行。当表进行归一化,可以按城镇和排序递减计数:
WITH rec(town, remain)
AS (
SELECT SUBSTR(search_town, 0, INSTR(search_town, ',')) -- Before ,
, SUBSTR(search_town, INSTR(search_town, ',')+1) || ',' -- After ,
FROM t1
UNION ALL
SELECT SUBSTR(remain, 0, INSTR(remain, ',')) -- Before ,
, SUBSTR(remain, INSTR(remain, ',')+1) -- After ,
FROM rec
WHERE LENGTH(remain) > 0
)
SELECT town
, COUNT(*)
FROM rec
GROUP BY
town
ORDER BY
COUNT(*) DESC
想法从这个blog post。工作实例at sqliteonline。